diff --git a/psutil/arch/netbsd/specific.c b/psutil/arch/netbsd/specific.c
index cab60d60..a87008c4 100644
--- a/psutil/arch/netbsd/specific.c
+++ b/psutil/arch/netbsd/specific.c
@@ -312,42 +312,48 @@ psutil_get_proc_list(kinfo_proc **procList, size_t *procCount) {
 
 char *
 psutil_get_cmd_args(pid_t pid, size_t *argsize) {
+    int argc;
+    char *argv;
+    size_t len;
+    int st;
     int mib[4];
-    ssize_t st;
-    size_t argmax;
-    size_t size;
-    char *procargs = NULL;
 
     mib[0] = CTL_KERN;
-    mib[1] = KERN_ARGMAX;
+    mib[1] = KERN_PROC_ARGS;
+    mib[2] = pid;
+    mib[3] = KERN_PROC_NARGV;
+        
+    len = sizeof(argc);
 
-    size = sizeof(argmax);
-    st = sysctl(mib, 2, &argmax, &size, NULL, 0);
+    st = sysctl(mib, __arraycount(mib), &argc, &len, NULL, 0);
     if (st == -1) {
         PyErr_SetFromErrno(PyExc_OSError);
         return NULL;
     }
 
-    procargs = (char *)malloc(argmax);
-    if (procargs == NULL) {
-        PyErr_NoMemory();
+    mib[3] = KERN_PROC_ARGV;
+    len = 0;
+
+    st = sysctl(mib, __arraycount(mib), NULL, &len, NULL, 0);
+    if (st == -1) {
+        PyErr_SetFromErrno(PyExc_OSError);
         return NULL;
     }
 
-    mib[0] = CTL_KERN;
-    mib[1] = KERN_PROC_ARGS;
-    mib[2] = pid;
-    mib[3] = KERN_PROC_ARGV;
-
-    st = sysctl(mib, 4, procargs, &argmax, NULL, 0);
+    argv = malloc(len);
+    if (argv == NULL) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+    st = sysctl(mib, __arraycount(mib), argv, &len, NULL, 0);
     if (st == -1) {
-        free(procargs);
+        free(argv);
         PyErr_SetFromErrno(PyExc_OSError);
         return NULL;
     }
 
-    *argsize = argmax;
-    return procargs;
+    *argsize = len;
+    return argv;
 }